Innosetup incorrect/mess compression algorithm possibibility

[Herman Semm]

Hi Mr. Jordan Russell and Mr. Martijn Laan..

I have made installer with Innosetup compared to NSIS and Advanced Installer, as below:

[Setup]
Compression=lzma2/ultra
SolidCompression=yes
InternalCompressLevel=ultra

1. Repacking 8 CardGames Apps -> raw size 2,376,639,265 bytes, installer result's size:
- Advanced Installer v23.3.0 -> 673,479,034 bytes
- NSIS v2.51 -> 638,809,347 bytes, there's no big result difference when using NSIS 3.11.
- Innosetup v6.6.1 -> 1,444,961,071 bytes, there's no big result difference when using Innosetup 5

You can see that Innosetup installer result too big size difference, compared to other.


But with raw files with total size under/or 500 MB's, there's no significant differences of installer result sizes, as below:

2. Repacking PhotoScape X Pro v.4.2.8 -> raw size 482,521,249 bytes, installer result's size:
- Advanced Installer v23.3.0 -> 382,714,191 bytess
- NSIS v2.51 -> 382,672,826 bytes, there's no big result difference when using NSIS 3.11.
- Innosetup v5.5.3 -> 376,135.093  bytes, there's no big result difference when using Innosetup 6


I think there must be an incorrect/miss with Innosetup compression algorithm.

I've tried/tested with Innosetup 5 and Innosetup 6 older as above, on both Windows 10 and Windows 11, and they're produced the same results.


Please make your own test with raw files total sizes about as I've used above.

I hope you could fix them soon to next version.


Best regards,

Herman Semm